The present disclosure relates to a document cover used for pressing a document on a document platen to read an image on the document, an image reader having the document cover, and an image forming apparatus.
The following technology has been known as a conventional document cover used for pressing a document on a document platen to read an image on the document. In this technology, an apparatus main body with a document carrying glass (document platen) is provided with a document cover (sheet document feeding device) for pressing a document from above such that the document cover is turnable. The document cover has a hinge. The hinge has a hinge shaft and a slide rail extending from the hinge shaft. The slide rail is inserted slidably into the apparatus main body having the document carrying glass. The document cover is supported so as to be able to turn around the hinge shaft with respect to the apparatus main body.
In the technology described above, a book document, thicker than a pile of sheets, is occasionally placed on the document carrying glass. FIG. 17 is a lateral cross-sectional diagram schematically showing the document cover used in this case. The document cover 300 is supported so as to be turnable with respect to a contact glass 225 (document platen), by fitting a hinge shaft 301 to a fitted part 401 disposed at an upper end of a slide rail 400. Once placing a thick book document B on the contact glass 225, a user presses down the near side (left-hand side in the diagram) of the document cover 300 so that light outside the machine does not enter the contact glass 225. As a result, the document cover 300 and the slide rail 400 form an acute angle therebetween. Then, the hinge shaft 301 and the fitted part 401 are positioned at a rotation angle different from the one obtained when a regular sheet is placed on the contact glass 255 in the document cover rotational direction. This can prevent the hinge shaft 301 from falling off the slide rail 400 (arrow D17).
The present disclosure was contrived in view of the problem described above and is capable of preventing disengagement of a component constituting a hinge of a document cover.